Personal vaporization devices that store substances to be vaporized include, for instance, inhalers for asthma treatment, and medicinal and recreational vaporization devices for personal use. Some personal vaporization devices have air intake holes at or near the bottom of a chamber or tank for containing the electronic liquid (“e-liquid”). Upon an inhalation of the user air is drawn into the device and flows over or past a heating coil that vaporizes the e-liquid into a vaporized product that travels through a mouthpiece of the device to be inhaled by the user. However, air holes disposed at the bottom of an e-liquid tank promotes leakage of the e-liquid out of the device through the holes. A solution to this problem is to locate air intake holes at a top side of the e-liquid tank, referred to as a top airflow tank.
The current state of the art for top airflow tanks brings air into a vapor tube assembly from a port by the mouth piece. The air travels away from the mouthpiece in an annular space between a center tube that feeds vapor to the mouthpiece and an annular tank. One such design is illustrated in U.S. Patent Application Publication No. 2018/0153220. However, problems exist with the current state of the art.
Ambient air traveling down around the center tube helps pull up vapor from the heating coil but does not pass through the heating coil. Therefore, the ambient air in existing designs pulls out only a fraction of the vapor from the region of the heating coil as compared to a design where the ambient air travels through the heating coil and pulls out substantially all the vapor therefrom.
Another problem of current top airflow tank designs is that the device and e-liquid start off at room temperature, but puff after puff raises the temperature of the device and the heating coil because there is insufficient airflow through the device and especially through the heating coil. Elevated internal temperatures can cause the e-liquid to thin and change properties. However, ambient air flowing through the coil has a beneficial cooling effect on the device by cooling the heating coil, which helps keep the e-liquid from thinning and over saturating the heating coil and changing the properties of the e-liquid, which ensures a consistent vapor production on every puff. Therefore, there is a need for a top airflow tank that includes airflow through the heating coil.